Are those 6" radius turns on the inside of the "banked" end? Which direction are the cars coming into that corner from -- the long straight or the short one after the esses? The short one would be better. Otherwise, whichever car is racing on the inside lane there is going to have a tough time keeping up. That lane doesn't get very much time on the outside so it's going to be challenging for them.
6" curves can flow good, or can be a royal headache. A lot of it just depends on where it is. My little table has (2) 6" 1/4 curves and one gives me no issues whatsoever. Heck, I don't even have guard rail on it. The other one causes trouble consistently, and I've gone as far as far as propping it up with a 9" curve to add a little bank to it and it still is a pain with spin outs. It just depends on what leads into them and out of them. Having them at the end of a long straight can be an issue, but if you're driving the worst lane all the time you will get used to it.